The Gravity CH423 I2C 24 Digital IO Expansion Module extends your microcontroller with 24 additional digital output/input pins over a standard I2C connection. Based on the CH423 chip, it provides 8 GPIOs with interrupt support and 16 dedicated GPOs.

The built-in current drive circuit delivers up to 15 mA continuous current per pin, allowing it to statically drive 24 LED tubes or dynamically drive up to 128 LEDs — making it well suited for LED matrix displays, light cubes, and indicator arrays.

Key Features

• 24 Digital Pins – 8 GPIO (with interrupt) + 16 GPO
• Built-In Current Drive – Up to 15 mA continuous per pin
• I2C Interface – Gravity-compatible 4-pin connector
• Wide Voltage Range – 3.3 V to 5 V supply
• LED Drive Capability – Static drive for 24 LEDs or dynamic drive for up to 128 LEDs

Specifications

• Chip: CH423
• Power Supply: 3.3–5 V
• Static Current: 1 mA
• IO Continuous Drive Current: 15 mA
• Interface: I2C
• I2C Address Range: 0x20–0x3F (occupies the full range; cannot share with other I2C devices at these addresses)
• Operating Temperature: −20 °C to +80 °C
• Board Size: 45 mm × 37 mm (1.78″ × 1.46″)

Ideal For

• LED tube and dot matrix displays
• Light cubes and LED arrays
• GPIO expansion for pin-limited microcontrollers
• Indicator panels and control systems

Package Contents

• 1× Gravity CH423 I2C 24 Digital IO Expansion Module
• 1× Gravity 4-pin I2C/UART sensor cable

Resources

• Product Wiki
• Schematic (PDF)
• Dimensions (PDF)